Improvement in derricks



JOHN E. WALSH, OF NEW YORK, N. Y.

IMPRVEMENT IN DERRlcKs.

Specification forming part of Letters Patent No.`138,2l5, dated April22, 1873; application filed March '7, 1873.

To all whom it may concern: I g

Be it known that I, JOHN E. WALSH, of the city, county, and -State ofNew York, have made certain Improvements in Derricks, of which thefollowing is a specification:

The invention relates to derricks used in hoisting freight from the holdof a vessel, or lowering such freight into the hold; and it consists inthe construction and arrangement of the parts which make the derrick amore perfect device, as will be fully hereinafterdescribed.

In the drawing, Figure 1 represents the front view of the derrick; Fig.2, a plan or top view; and Fig. 3, enlarged details of some of theparts.

A represents an upright movable mast secured in the step a, which ismade fast to any permanent and convenient floor, platform, or vesselsdeck by means of screw-bolts or their equivalents, so that the step ciand mast A can be readily removed, as may be desired. A is a removableswinging cap, formed by the two horizontal beams and two uprights, a a',at their extremities. These uprights a are made fast to the horizontal'beams by going through the ends thereof. The whole cap can be removedfrom the mast at will. The cap A thus formed has center holes in thehorizontal beams, which receive the upper end of the mast, and canfreely revolve thereon. The cap A is supported and strengthened bythimbles a" and a. Thimble a is fast upon the under side of the upperhorizontal beam, and embraces the upper end of the mast A, and restsupon a shoulder on said mast, while thimble a" is free to revolve aroundmast A at a distance below the lower horizontal beams, and bears upon apermanent thimble,a5, fast on the mast A. a4 a4 are braces secured toopposite sides of a thimble, af", and extend upward and outward to theunder side of the lower horizontal beam near its outward ends, wherethey are permanently secured thereto, giving strength to resist lateralstrain. B B are swinging arms or booms that at their inner ends arepivoted to and turn around the upright pieces a of the cap A. Arms Bhave vertical slots b, as seen in Fig. 3, to carry travcling blockstherein, and are supported by bracerods b b' b', which go from the armsto a revolving thimble or eye, b, on the upper ends of the uprights a ofthe cap A', and are capable of sustaining any load put upon the swingingarms or booms. The vertical slots b in the swinging arms B are wider ontheir upper sides than on the lower, in order to form ledges or tracks 1to support the friction-wheels 2 of the traveling blocks C, in which thehoisting-rope works whenin operation. Only two swinging arms carryingtraveling blocks are shown; but it is evident that, when necessary,

`two more can be added by duplicating the horizontal beams and uprightsin the cap A, and forming them into a single cap or revolving head, towhich two more arms can be attached. O O are the traveling blocks,containing sheaves c c and friction-wheels 2 2 on their outer sides tobearupon the ledges or trucks 1 of the slot b in arms B, and are capableof travelin g horizontally the whole length of the slots in the arm B,as occasion may require, to accommodate the position of the weight to beraised, or where the weight shall be deposited. l) D are windlasses forwinding the hoistingrope upon, and have Winches d d to operate the same;when worked by hand are fast in strong frames d that are immovable; andto the shaft of each windlass is a ratchet or toothed wheel, d, that isheld from unwinding by the drop-pawls LZ. E E are hoistingropes aroundthe winding-cylinder of the windlass; thence over one of the pulleys e enear the inner ends of the swinging arms B; thence horizontally over andaround one of the pulleys c in traveling'block C thence downward tohoisting-block F and around a sheave therein; thence up and aroundanother pulley, c, in the traveling block C; then down around anothersheave in hoisting-block F then up, and the end secured to an eye in theunder side of the traveling block G. Gr G are windlasses made fast to aplatform or iioor, and are similar in construction to windlasses D, andare used for regulating the traveling blocks C to be at the properhorizontal distance from the mast A by means of the rope g windingaround the cylinder of 4windlass G; thence upward over one of thepulleys e at the inner end of slot b in the swinging arm B; thencehorizontally over pulley g' at the outer end of the swinging arm B; thendown. and attached to UNITED STATES PATENT OEEIGE.

an eye on the outer end of the traveling block (y), by which arrangementthe traveling block and its weight are made to be at any desiredldistance from the mast or from the end of the swinging arm. In order toproperly brace the derrick and keep it from swaying under the weight tobe raised, guys h are made fast to the ends of the top horizontal beamof the cap A', and strained tight around cleats h on the platform, andwhen the cap A is to be turned on the mast these guys are used for thepurpose, and when the cap is in the right position the guys are fastenedby the cleats to hold it in such position. h h are guy-ropes attached tothe outer ends ofthe swinging arms B, and by which the arms B are swungaround to any desired position, when the guys h are made fast to cleatsh h", when the position of the arm is secured.

By this construction of the revolving cap and swinging arms in a derrickgreat convenience is had over the ordinary derrick in raising orlowering the weight W in a perpendicular direction, be the positionofthe weight W what it may, if in reach of the swinging arm, which doesawaywith the immense friction that is had when the weight being raisedor lowered is moved horizontally in contact with the ground or floor onwhich it rests.

It is obvious that other power than manual or hand can be applied to thewindlass to operate the raising or lowering of the weights or packagesbeing handled. A

Having thus described my invention, what I claim, and wish tovseeure byLetters Patent, 1S

1. In a hoisting-derrick, the removable revolvin g cap or head A', whenconstructed and operating upon the mast A in the manner substantially asdescribed and shown.

2. In a hoisting-derrick, the swinging arms B, in combination with therevolving cap A and mast A, constructed to operate in the mannersubstantially as described.

3. The swinging arm B, having slot b with ledges or tracks l therein,substantially as and for the purposes described.

4. The combination of the hoisting-block C, having sheaves c c andfriction-rollers 2, with the swinging arm B, having the slot b andledges or tracks 1 therein, substantially as and for the purposesdescribed.

5. The combination of the windlass D, hoisting-rope E, pulley e, andtraveling block C with the swinging arm B, in the manner substantiallyTas described.

6. The combination of the windlass G, rope g, pulleys e and g with thetraveling block C and swinging arm B, substantially as and for -thepurpose specied.

7. The combination of the swinging arm'B that carries the travelinghoisting-block C with the guy-ropes la h Vand cleats h" hf,substantially as and for the purpose described.

JOHN E. WALSH.

Witnesses:

GEORGE S. McKAY, HENRY W. RAYMOND.

